FR2744044A1 - INSTALLATION FOR THE TREATMENT OF WASTE SUCH AS URBAN WASTE OR HOUSEHOLD GARBAGE - Google Patents

Abstract

Household waste treatment plant, comprising: - two treatment lines arranged in parallel, namely an incineration line and a waste fuel production line; - means for the recovery, transfer, storage of waste fuel and supply with waste fuel to the incineration system; - means of selective supply of the two channels with waste, and for the incineration channel, with waste fuel, depending on the incoming flow of waste and the treatment capacities of the two lines, so that, during the or peak periods of the arrival of waste, the waste fuel production channel is in operation, the waste fuel then produced feeding the incineration channel outside of this or these peak periods.

Description

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  The invention relates to a treatment plant

  waste such as urban waste or household waste.

  Waste of this type has been a long time, and are

  still sometimes stored in landfills.

  The raw landfill, which is to dump the garbage directly into a hole such as an old

  career, without special precautions, is prohibited.

  Organic matter in household waste is fermented by aerobic and anerobic microorganisms. This mineralization is obtained only after serious inconveniences and inconveniences: repulsive appearance, unpleasant odors, development of

  rodents, fires, pollution of aquifers.

  Controlled landfill mitigates some of these disadvantages. It consists in covering the garbage with a layer of topsoil, allowing the maintenance of the humidity necessary for the aerobic fermentation, which can take place thanks to the air contained in the garbage

in bulk.

  Controlled landfilling is costly for various reasons such as the need to seal

  discharge area and treat leachate.

  Moreover, the volumes to be stored are often very important even if densification is carried out by

  preliminary grinding or using compactors.

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  Finally, the French law of 13 July 1992 stipulates that (Article 2-1): "As from 1 July 2002, disposal facilities for storage will be allowed to receive only ultimate waste" Landfill garbage

will be excluded.

  Composting or accelerated fermentation uses the aerobic fermentation of household waste to prepare a compost for use as an agricultural amendment. Composting is usually done in

cells or digesters.

  Like landfilling, composting poses many problems, for example in terms of odors, volume of waste to be treated. In addition, compost made from household waste is not always

  of good quality and finds it difficult to flow.

  In addition, composting requires sorting

  waste, as well as grinding.

  Indeed, some materials may have a disadvantage for the progress of the fermentation or for the quality of the compost, while others are recoverable

(metals, rags).

  Apart from the techniques of storage and destruction, partly of biological origin, waste, other techniques of stabilization or

combustion are used.

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  Incineration remains the most convenient process

  to eliminate garbage or urban waste.

  In this technique, household waste and ordinary industrial waste are reduced to solid residues

  and gaseous in the combustion chamber of an oven.

  Fumes can be used as a source of energy for

  through a recovery boiler.

  The heat energy thus recovered can be used either directly for the heat requirements of housing or industrial processes, or indirectly

to produce electricity.

  Slag is the solid waste resulting from the combustion of garbage. After defrosting, they can be used for filling embankments or used as underlays of roads, subject to

  meet regulatory standards.

  For the incineration of garbage to be properly carried out, certain conditions are indispensable. In particular, the temperature at the moment of combustion must be homogeneous and stable, so as to

ensure complete combustion.

  The combustion temperature must be higher than 850oC and not exceed about 1000 C to prevent

ashes clog the oven.

  As a result, an important feature of the incineration technique is that

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  facilities must be very precisely established based

the daily influx of garbage.

  Household waste is a material that needs to be processed very quickly without being able to

be stored as is.

  A technical problem therefore arises in the case of strong variations, periodic or otherwise, of this flow

garbage.

  This is the case for cities with a high periodic variation in populations, especially those with a tourist vocation. These cities have to deal with a tonnage of waste to be treated in a much larger quantity during a

  short period than during the rest of the year.

  Faced with this problem, several solutions can

to be considered.

  The classic solution is to oversize the incineration plant to allow for the treatment of all household waste at the time it is produced. This solution, sometimes envisaged for example in the case of incineration plants comprising several independent modular lines, leads to higher investment costs, than would have been necessary if the same tonnage of garbage had been produced. a

  more consistent way in time.

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  In addition, equipment is underutilized

outside the peak period.

  Another solution, sometimes implemented, is to divert garbage that can not be

absorb the incineration plant.

  As mentioned above, this solution poses many problems in terms of environmental protection, and will no longer be acceptable after 2002

  given the regulations mentioned above.

  A third solution is to transform garbage that can not be absorbed by the incineration plant.

combustible waste.

  Several major disadvantages have emerged for

this sector.

  The fuel conventionally used for the

  drying is noble (fuel, coal, wood) so expensive.

  Dehydration is often insufficient for the fermentation of waste fuel and the risk of

fire in the storage.

  The sometimes large distances between the production and the use of the waste fuel generate

  significant transportation and handling costs.

  The reuse of waste fuel in unsuitable boilers induces significant nuisances (intermediate storage, high rates of unburnt, air pollution).

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  A fourth possibility is to implement a sorting / grinding / composting process for

seasonal surpluses of garbage.

  This type of industry combines the disadvantages of

landfill and composting.

  Another solution is to implement

  biological stabilization and storage.

  This process, still experimental, presents

many disadvantages.

  In particular, there is a risk of fermentation in

  summer period, so of smells and catch of fire.

  In addition, the storage volume is very important. It is therefore clear from the state of the art that, while incineration remains the most convenient and widespread method of treating urban waste and household waste, no satisfactory solution has yet been found for

  the treatment of seasonal surpluses of garbage.

  One of the objects of the invention is to provide a simple and economical solution to the problem set out above, this solution also satisfying the requirements of

Environmental Protection.

  In view of this object, the invention relates in a first aspect to a treatment plant of

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  urban waste or household waste, including, from an arrival of waste or garbage: - two treatment channels for such waste or garbage, arranged in parallel, namely an incineration and a waste fuel production sector; means interposed between the exit of the waste fuel production die and the entry of the incineration die for the recovery, the transfer, the storage of the waste fuel and the feeding with the waste fuel of the waste die. incineration; - Selective means of supplying the two sectors with waste, and for the incineration sector, with waste fuel, according to the arrival flow of the waste and the processing capacities of the two sectors, so that, during or the peak periods of arrival flow of waste or garbage, the waste fuel production line is in operation, the waste fuel then produced supplying the incineration sector outside this or these peak periods. The incineration line comprises, upstream to downstream, connected by connecting or transfer means: - one or more incineration furnaces; - a set of one or more heat recovery boilers; a unit for treating the combustion gases; and

  - a purified exhaust gas chimney.

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  The waste fuel production system comprises, upstream to downstream, connected by the connecting or transfer means: means for pre-sorting the waste or garbage; one or more grinders; an electromagnetic defrosting unit; a screening unit; one or more dryers; one or more presses producing the waste fuel; -a covered storage shed with handling equipment; -a fuel transportation system waste towards

  the hoppers of the incineration furnaces.

  According to other characteristics, the installation comprises means for connecting or transferring upstream the screening unit of the waste fuel production line and, downstream, the incineration furnace (s) of the waste stream. incineration, so that the organic fraction recovered from the first is sent

in the second or second.

  According to still other characteristics, the installation comprises means of connection or transfer between upstream the exit of the fumes from the incineration furnace (s) and downstream the entry of the dryer (s) of the waste fuel production die. , so that the dryer (s) are fed by the gases

  combustion of waste or garbage.

  According to still other characteristics, the installation comprises means of connection or

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  transfer between the output of the dryer (s) of the waste fuel production die and the combustion treatment unit of the incineration die so as to ensure the treatment of the drying gases. According to still other characteristics, the installation also comprises means for dosing the feed of the incineration furnace (s) with the waste or garbage on the one hand, the waste fuel

on the other hand.

  According to still other characteristics, the installation is such that incineration furnaces are associated with a slug recovery and disposal device, a de-ironing unit for said bottom slag and an ash disposal system, and that at the (to) boiler (s) are associated a water treatment station, a set of pumps and a degasser, an air condenser, a

  heat exchanger, a turbo alternator group.

  The waste fuel production die also comprises a set of regulation of the temperature and the drying time; a device for regulating the flow of drying gases with fire detection system and automatic extinction in case of

catch of fire.

  The press (s) of the waste fuel production chain may be associated with one or more

  separators, crushers, mixing hopper.

  The installation is such that the incineration sector has a specific capacity to allow a

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  optimized average operation taking into account the average tonnage of waste or garbage, excluding the peak period (s), and the tonnage of waste fuel produced during the peak period (s) and disposed of in the incineration process outside the period (s) peak, and that the waste fuel production chain has a defined capacity to allow the treatment of additional streams of waste or garbage corresponding to the

at peak periods.

  The installation is located on one and the same site

  and the storage of the waste fuel is covered.

  According to a second aspect, the invention relates to a method of operating an installation as described above, in which process: the incineration die operates or can operate continuously, subject to technical stops, in particular alternating ; the waste fuel production line operates or can operate in the peak period (s); - the waste fuel produced is incinerated outside the peak period (s), when the economic conditions of the thermal recovery are optimal. The waste fuel production line operates or can operate also during shutdowns

  techniques of incineration lines that are shifted.

  In one embodiment of the method, there is a summer peak period of about two months, the waste fuel being incinerated during a period of

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  approximately four to eight months and there is a technical shutdown period of approximately one month for each of the incineration lines. Other objects and advantages of the invention

  will appear in the following description, realized

  with reference to the accompanying drawings in which: - Figure 1 is a diagram showing the organization of an installation implementing the method according to the invention; FIG. 2 is a histogram representing the monthly flows of household refuse as encountered in certain tourist cities, and showing the principle of seasonal clipping of garbage as implemented.

by the invention.

  An installation according to the invention comprises a die 1 of incineration and a die 2 of production of

waste fuel.

  The incineration line 1 comprises a zone 3 for receiving household waste comprising one or more weighbridge and a garbage reception pit. In this garbage reception station, trucks

  are identified and the waste is weighed.

  The waste reception and storage pit may be located in a closed hall with a

  laborer for delivery trucks.

  At least one crane or equivalent handling system is arranged in such a way that it can

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  take waste in the pit to supply the incineration sector 1 and the sector 2

  waste fuel fabrication.

  In one embodiment, the supply of each of the incineration lines may be constituted by a hopper, possibly equipped with a charge regulator and a sealed door at its upper end, said hopper being located upstream at least

  a combustion chamber of an incineration furnace.

  The incineration line 1 comprises at least one

4 incineration oven.

  Such an oven 4 may be for example grid or

fluidized bed.

  The slag 5 from the combustion of garbage

  in the oven 4 are taken up and evacuated after deferraillage.

  The incineration die 1 also comprises a heat recovery boiler assembly 6, with

  sweeping system, economizers and superheater.

  This set of heat recovery boiler 6 provides energy 7, for example usable for district heating, or for producing electrical energy. The gases from the incineration furnaces 4, after cooling in the energy recovery boiler or boilers 6, are cleaned in a unit 8 for treating smoke, humid or semi-wet or other. After treatment

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  flue gases, pollutant levels are

in accordance with the standards in force.

  Any fly ash contained in these gases are extracted and treated according to the standards in force. In general, residues of household waste incineration fumes 9, conventionally called REFIOM, are stabilized before storage in a site.

landfill.

  The purified gases 11 are eliminated by the stack 10,

  height determined by regulation.

  The die 2 for manufacturing waste fuel comprises a first station 12 for receiving household waste. In one embodiment, this first item 12

  is common to zone 3 of die 1.

  The handling of garbage in the die 2 is obtained by means of the traveling crane with grapples or equivalent handling means, these handling means also feeding the incineration die 1. In the die 2, the sorting of the garbage can, in a embodiment, be executed partly automatically. For example, household waste can be ballistic, aeraulic and magnetic sorted in order to separate different constituents such as

  plastics, glasses and metals.

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  Sorted household waste passes into a unit

13 grinding.

  Following the grinding step, the garbage is stripped in an electromagnetic defrosting unit 14. The resulting ferrous metals are recovered for

  be used in foundry or equivalent.

  The garbage deforted and crushed are then

  screened in an automatic screening unit 16.

  This unit 16 makes it possible, among other things, to separate the

organic fraction 17.

  Finally, a unit 18 for drying and pressing rubbish, crushed and screened garbage leads to the formation of waste fuel 19, in the form of small

  cylinders with a length of a few centimeters.

  The unit 18 comprises a regulation unit of

temperature and drying time.

  The unit 18 furthermore comprises a device for adjusting the flow rate of the drying gases with a fire detection system and automatic extinguishing by

  water spray in case of fire.

  The unit 18 also comprises a cyclonic separator, followed by a vibrating separator, a magnetic drum, a finishing mill, a hopper

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  mixing machine and a press capable of producing elements

  tablets with pressure regulation.

  During the treatment carried out in unit 18, water 20 is evaporated in a significant amount, the waste product 19 thus having a humidity

very low, less than 10%.

  As a result, the waste fuel 19 can be

  stored in a storage warehouse 21, covered.

  The waste fuel has a considerable heating value, for example of the order of

3500 to 3800 th / t.

  The incineration line 1 and the waste fuel production line 2 are suitable for

work in synergy.

  Indeed, the waste fuel 19 produced by the die 2, possibly stored in the warehouse 21 can

  serve as fuel in incineration furnaces 4.

  The feeding of incineration furnaces 4 with waste fuel 19 is entirely automated. The waste fuel can be introduced into the feed hopper of each of the incineration furnaces where

mixed with household waste.

  The organic fraction 17 recovered during the screening in the die 2 is returned to the refuse collection pit in an area where it can be

  mixed with household waste to be cremated.

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  The combustion gases 22 for drying the screened household refuse come from the incineration furnaces 4 and are, after passage through the unit 18 of the die 2 reintroduced into the incineration line 1 in the unit 8 for treating the gases. of combustion. In one embodiment of the method of the invention, the die 1 operates continuously, apart from the technical stops for example maintenance, and the die 2 operates only during certain periods of the year, periods that may correspond, for example to a large influx of waste due to an influx of tourists. FIG. 2 represents a histogram of the quantities of garbage treated during the year, in the preferred embodiment of the method of the invention.

presented above.

  The quantities of garbage incinerated in the

  die 1 are represented in light gray.

  Apart from the period of alternating technical stop of each incineration line, the sector 1

  eliminates a substantially constant amount of garbage.

  The quantities of garbage transformed into waste fuel are shown in black. During the technical shutdown period of the incineration furnaces of the die 1, the die 2 absorbs all the refuse

can be incinerated.

  In the case where the die 1 comprises only one furnace, the die 2 is able to absorb the totality of

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  Daily intake of garbage, allowing a temporary stop

said oven.

  Sector 2 is also able to absorb the amount of garbage corresponding to the seasonal surplus

  linked for example to a tourist influx.

  The waste fuel produced by the die 2 can be stored, as mentioned above, and incinerated

by the sector 1.

  In one embodiment of the method of the invention, the waste fuel is incinerated during a "hollow" period 26 that is to say outside the seasonal period 27 or the daily quantity of garbage is the

more important.

  Incinerated waste fuel 28 represents a fraction of the raw garbage load introduced into

the ovens 4.

  Some advantages of the method and of the installation implementing the method of the invention will now

to be presented.

  Firstly, the integrated concept of manufacturing, storage and incineration of waste fuel leads to economies of scale in equipment and

  the operation of an incineration site.

  For example, the method of the invention will be compared to a solution all incineration in the case

  of a city located in tourist region.

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  The assumptions of this comparative study are as follows. The annual amount of household waste is 220 000 tonnes or 18 333 tonnes / month, or

, About 5 tons / hour.

  The additional amount related to summer tourism is 20 000 tonnes over two months, or 10 000 tonnes / month,

about 14 tons / hour.

  The alternating technical stops of the two ovens

incineration are one month / year.

  An incineration furnace is provided, in addition to the two furnaces mentioned above, in the case of the all incineration solution. This oven is put into operation during the technical stops of the two other ovens, and incinerates the excess

seasonal garbage.

  This additional oven has a capacity of at least

equal to 14 tonnes / hour.

  A waste fuel production line is provided in the case of implementing the method of the invention. This line has a capacity of 15 tons / hour

  approximately, with an availability factor of 95%.

  The annual quantity of garbage treated in the waste fuel line is 20 000 tonnes during the summer

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  and 18,333 tonnes during alternating technical stops

  of the two furnaces of the incineration line.

  The facility operates for five months in incineration with waste fuel and seven months in incineration without the manufacture of waste fuel. It runs for four months with waste fuel fabrication and eight months

  without manufacturing waste fuel.

  On the basis of these assumptions, the average investment per tonne of waste treated per year is 25% lower by implementing the process of the invention than by

  choosing the die all incineration.

  The method according to the invention and the installation

  implementing this method have other advantages.

  For example, load variations are perfectly accepted by the waste fuel manufacturing line, which is almost immediately put into service and shut down. In particular, the method of the invention avoids oversizing the incineration plants to absorb the seasonal peaks of delivery in household waste, these oversized factories being expensive in investment and under used in

outside peak periods.

  The storage and incineration of waste fuel outside peak periods allows energy recovery at a cost that is economically attractive, for example during periods of high energy demand.

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  Thus, in the case where the quantities of garbage to be treated are maximum in summer, a period unfavorable to energy recovery, the manufacture of waste fuel and its storage allows its subsequent incineration, for example in winter. The waste fuel is stored on the site, so there is no transportation costs. The production of waste fuel being carried out at the site of the incineration unit and during its operation, drying can be achieved by a portion of the gases leaving the incineration furnaces at a time when the thermal energy would be poorly recoverable, hence a significant energy saving. The energy recovery of the installation is improved compared to conventional processes due to: - the relatively high calorific value of the waste fuel, approximately 3600 kcal / kg, and its possible incineration in a period when the valuation is higher; - synergistic operation, lines

* incineration and waste fuel production.

  The method of the invention and the plant implementing this method do not harm the environment, for various reasons such as the fact that no residue is rejected, the ferrous metals being recycled, the organic fraction resulting from the screening. being incinerated, and the combustion gases used for drying the waste fuel

being recycled and processed.

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  The impact on the environment is identical to that of an incineration plant, which is perfectly regulated.

and controlled.

  Finally, an architectural project of the whole formed by the incineration sector and the waste fuel manufacturing sector allows to design a unit well

integrated into the site.

  if the invention relates to the assembly formed by an incineration die and a waste fuel manufacturing die, it is understood that the invention also relates to the adaptation of a waste fuel manufacturing die to a existing incineration line, as well as, where appropriate, the adaptation of an incineration line to a waste fuel production line, the combination of the two lines forming a utilization treatment unit

flexible, economical, ecological.

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Claims (19)

  1. Installation for the treatment of urban waste or household waste, including, from an arrival of waste or garbage: - two treatment channels for such waste or garbage, arranged in parallel, namely an incineration line and a waste stream; waste fuel production; means interposed between the exit of the waste fuel production die and the entry of the incineration die for the recovery, the transfer, the storage of the waste fuel and the feeding with the waste fuel of the waste die. incineration; means for selectively feeding the two waste streams, and for the incineration system, waste fuel, depending on the arrival flow of waste and processing capacity of the two lines, so that, during the peak periods of arrival of the waste stream, the waste fuel production line is in operation, the waste fuel then produced supplying the incineration sector outside this or these periods of point.   2. Installation according to claim 1, characterized in that the incineration die comprises, upstream to downstream, connected by connecting means or transfer: - one or more incineration furnaces; - a set of one or more heat recovery boilers; a unit for treating the combustion gases; 23 2744044 and   - a purified exhaust gas chimney.   3. Installation according to claim 1, characterized in that the waste fuel production die comprises, upstream to downstream, connected by the connecting means or transfer: - means for pre-sorting of waste or garbage; - one or more grinders; - an electromagnetic defrosting unit; - a screening unit; - one or more dryers; one or more presses producing the waste fuel; - a covered storage shed with handling equipment; - a waste transportation system   to the hoppers of the incineration furnaces.   4. Installation according to any of the   Claims 1 to 3, characterized in that it comprises   linking means or transfer between upstream the screening unit of the waste fuel production line and, downstream, the incineration furnace or incineration furnaces, so that the organic fraction recovered from the first be sent in the second or second.   5. Installation according to any of the   Claims 1 to 4, characterized in that it comprises   connecting means or transfer between the upstream smoke outlet of the incineration furnace (s) and downstream the entry of the dryer (s) of the production line of 24 2744044   waste fuel, so that the dryer (s) are fed by the combustion gases of the waste or garbage. 6. Installation according to any of the   Claims 1 to 5, characterized in that it comprises   connecting means or transfer between upstream the outlet of the dryer (s) of the waste fuel production die and the combustion gas treatment unit of the incineration die so as to   ensure the treatment of drying gases.   7. Installation according to any of the   Claims 1 to 6, characterized in that it comprises   also means for dosing the feed of the incineration furnace (s) with the waste or garbage of a   on the other hand, the waste fuel on the other hand.   8. Installation according to any of the   Claims 1 to 7, characterized in that the ovens   of incineration are associated a device for the recovery and evacuation of slag, a de-ironing unit   said slag and an ash disposal system.   9. Installation according to any of the   Claims 1 to 8, characterized in that   boiler (s) are associated a water treatment station, a set of pumps and a degasser, an air condenser, a   heat exchanger, a turbo alternator group.   10. Installation according to any one of   Claims 1 to 9, characterized in that the die of   production of waste fuel also includes a set of regulation of the temperature and the duration of 2744044   drying; a device for regulating the flow of drying gases with a fire detection and extinguishing system automatic in case of fire.   11. Installation according to any one of revendicoins 1 to 10, characterized in that the press (s) of the waste fuel production line can be associated with one or more separators, crushers, mixing hopper.   12. An installation according to any one of   Claims 1 to 11, characterized in that the die   incineration has a fixed capacity to allow optimized average operation taking into account the average tonnage of waste or garbage, outside the peak period (s), and the tonnage of waste fuel produced during the peak period (s) and eliminated in the sector incineration outside the peak period (s) 13. Installation according to any one of   claims 1 to 12, characterized in that the die of   production of waste fuel has a defined capacity to allow the treatment of additional waste streams or garbage corresponding to the period (s) of point.   14. Installation according to any of the   Claims 1 to 13, characterized in that it is located on one and the same site.   15. Installation according to any one of   Claims 1 to 14, characterized in that the storage waste fuel is covered. 26 2744044   16. Operating method of an installation   according to any of claims 1 to 15, in   which: - the incineration line operates or can operate permanently, except for technical stops, notably alternating; the waste fuel production system operates or can operate in the peak period (s); - the waste fuel produced is incinerated outside the peak period (s), when the economic conditions of the thermal recovery are optimal. 17. Process according to any one of   claims 1 to 16, characterized in that the die of   production of waste fuel works or can operate also during technical shutdowns of   incineration lines, which are staggered.   18. The method of claim 16 or 17, characterized in that there is a summer peak period of about two months, the waste fuel being   cremated for a period of about four to eight months.   19. Method according to claim 18, characterized in that there is a technical shutdown period of one month   approximately for each of the incineration lines.